Venting means



W. W. VOSS VENTING MEANS April 26, 1949.

Filed July 25, 1946 Patented Apr. 26, 1949 2,468,385 VENTING MEANSWalter W. Voss, Chicago,

Corporation, Illinois Chicago.

Ill., assignor to Cardox III., a corporation of Application July 25,1946, Serial No. 686,247 22 Claims. (Cl. 62-1) 1 This invention relatesto new and useful improvements in venting means and relates morespecifically to the venting of carbon dioxide vapor from a fireextinguishing system that employs liquid carbon dioxide medium.

When carbon dioxide is employed for extinguishing a fire by the directapplication of the extinguishing medium onto the burning object ormaterial, it is essential that liquid carbon dioxide be delivered to thepoint or points of discharge if the most efilcient extinguishing actionis to be obtained. For that reason, the nozzles, or other devices,employed for eil'ecting the discharge are designed especially forhandling liquid carbon dioxide and are so positioned relative to thehazards as to make proper use of the snow and vapor type of dischargethat results from the handling of liquid carbon dioxide. It will beobvious, therefore, that the delivery of carbon dioxide vapor to suchdischarge nozzles, or other devices, will not help to any materialextent in eil'ecting extinguishment of a fire. It further will berealized that the time required to make the liquid carbon dioxideavailable for discharge at the nozzles is a very important factor inefi'ecting rapid extinguishment-of the fire, after it is discovered, sothat property loss will be held to a minimum.

In a fairly high percentage of fire extinguishing system installations,the layout or arrangement of the property to be protected is such thatrelatively long pipe lines must be provided to connect the source ofsupply of the liquid carbon dioxide to remotely located nozzles; or alarge capacity piping header must be provided to simultaneously supplythe extinguishing medium to a number of discharge nozzles protecting agiven hazard or to a number of branch pipe lines leading to differenthazards that may require protection at the same time.

It is the usual practice to so install carbon dioxide fire extinguishingsystems that the liquid carbon dioxide is normally kept confined in arefrigerated storage tank, or in a bank of high pressure cylinders,until a fire occurs and is then admitted to the piping system. Becausethe long pipe lines and/or the large capacity piping headers are atatmospheric pressure and normally are warm when the liquid carbondioxide is admitted thereto, there is considerable evaporation of theliquid carbon dioxide until a proper pressure and temperature conditiondevelops in the piping of the system.

The carbon dioxide vapor that is thus formed as the extinguishing 2 inthe piping system must be expelled through the nozzles before liquidcarbon dioxide can reach the nozzles for being discharged therefrom.Since all nozzle sizes must be established with reference to the pipingsystem so as to maintain a back-pressure at the nozzles that is inexcess of at least eighty pounds per square inch, absolute, the carbondioxide vapor is discharged through such nozzles at a much slower ratethan the nozzles will discharge liquid carbon dioxide. Another conditionthat results in a very slow discharge of the carbon dioxide vapor isencountered in installations involving several hazards and including oneor more small hazards which are protected by small capacity nozzlesreceiving their supply of carbon dioxide from large capacity pipingheaders. In such instance the relatively large amount of carbon dioxidevapor that is formed in initially filling the headers may require asmuch, or even more, time to be discharged through the said smallcapacity nozzles as is required to efi'ect the actual extinguishment ofthe fire with liquid carbon dioxide after it becomes available at thedischarge nozzles.

It is the primary object of this invention to provide apparatus forquickly freeing a fire extinguishing piping system of its initial chargeof carbon dioxide vapor so as to materially shorten the time requiredfor liquid carbon dioxide to reach the discharge nozzles.

A further important object of the invention is to provide apparatus forquickly expelling the initial charge of carbon dioxide vapor from theportions of the fire extinguishing system piping located in advance ofits liquid carbon dioxide nozzles and for automatically stopping theexpelling of carbon dioxide when liquid is available in the system.

Still another object of the invention is to provide the piping of acarbon dioxide fire extinguishing system with one or more normally openventing devices which will discharge carbon dioxide vapor from thepiping but will automatically close when liquid carbon dioxide reachessaid devices, whereby the discharge nozzles of the system, which arecalled upon to eiIect extinguishment of a fire, will be supplied withliquid very shortly after the carbon dioxide is first released into thepiping from its source of supply.

Other objects and advantages of the invention will be apparent duringthe course of the following description.

In the accompanying drawing forming a part of this specification and inwhich like numerals vvolved hazard is controlled by a valve Ill.

' aaeaeee 3 are employed for designating like parts throughout the same,

Figure 1 is a side elevational or schematic view of a fire extinguishingsystem having carbon dioxide vapor venting devices properly assembledtherein,

Fig. 2 is a side elevational view of one of the vapor venting devicesshown assembled in the system of Fig. 1,

Fig. 3 is a sectional view taken on line 3-3 of Fig. 2, and v Fig. 4 isa longitudinal sectional view of an expansion chamber that is includedas a part of the vapor venting device shown in the preceding figures.

In the drawing, wherein for the purpose of illustration is shown thepreferred embodiment of this invention, and first particularly referringto Fig. 1, the reference character 5 designates a I storage tank inwhich liquid carbon dioxide is to be confined at a controlledsub-ambient temperature, and its corresponding vapor pressure, by meansof an automatically controlled refrigerating system.- This type of bulkstorage for liquid carbon dioxide is more fully illustrated in the EricGeertz patents, No. 2,143,311, issued January 10, 1939, and No.2,202,343, issued May 28, 1940. The storage tank 5 is suitably confinedin a housing 6 and the space between the housing and the exterior of thetank 5 is filled with a suitable heat insulating material to retardabsorption of heat by the liquid carbon dioxide confined in the tank.

The tank 5 has suitably connected thereto a relatively large capacitypiping header 1 through which the liquid carbon dioxide is to bedelivered to any desired number of smaller capacity branch lines 8. Forthe purpose of normally confining the liquid carbon dioxide in thestorage tank 5 and for effecting its release into the header 1 when afire occurs, a suitable valve 9 is connected in the header 1 at adesired point relatively close to the tank 5, It will be appreciatedthat this valve 9 may be manually controlled or automaticaliycontrolled. If it is automatically controlled, it normally will beopened in response to the automatic detection of a fire at one or moreof the hazards being protected by the system.

When the system includes a plurality of branch lines, such as thosedesignated by the reference characters 8 for separately or independentlyprotecting different hazards, the admission of the liquid carbon dioxidefrom the piping header 1 into the branch pipe line 8 that leads to thein- In other words, one valve In is provided for each one of theseparate branch lines 8. These valves 10, which normally are referred toas selector valves, may be either manually or automatically controlledin the same manner as referred to above in connection with the valve 9,which is normally referred to as the master valve. 1

Each branch line 8 may have connected therein any desired number ofliquid carbon dioxide 'discharge nozzles, or other devices. Fig. 1discloses one of the branch lines 8 as having connected therein adischarge nozzle II which will directly apply the discharge of car-bondioxide onto the particular hazard that is to be protected thereby.Additionally, this branch line B is illustrated as having connectedthereto the hose-line l2, normally wound on the reel l3 and having thedischarge nozzle 14 connected to its outer end.

Because the master valve 9 is normally closed. so that the liquid carbondioxide will be confined pelled from the piping at url in the storagetank ii, the large capacity header i normally will be in a non-pressurecondition. That is to say, the pressure prevailing in the header 1between the master valve 9 and the selector valves III will correspondto that of the atmosphere. The header 1, also, will be at ambienttemperature. Consequently, when the liquid carbon dioxide is admitted tothe header I, as a result of opening the master valve 9, there will be asubstantial drop in pressure of the liquid carbon dioxide that isadmitted to the header. Also, the low temperature liquid carbon dioxideadmitted to the header will absorb a substantial amount of heat from theheader until the temperature of the header is loweredto that of thecarbon dioxide. Because of these two facts, or conditions, the liquidcarbon dioxide first admitted to the header 1, in filling this header,will evaporate and the header will be filled with carbon dioxide vapor.These same two conditions apply to the particular branch line 8 to whichthe carbon dioxide is admitted, by the opening of the proper selectorvalve Hi, to efiect delivery of the extinguishing medium to theparticular hazard that is being consumed by the fire. Consequently,liquid carbon dioxide first admitted to the branch line 8 that isinvolved will flash to vapor.

As has been pointed out above, the discharge nozzles II and H aredesigned for extinguishing a fire by the release of liquid carbondioxide. These discharge nozzles, therefore, are not suitable foreffecting a rapid liberation of the piping 1-8 of its initial charge ofcarbon dioxide vapor. Also, the discharge nozzles H and Hi cannot berelied upon to effectively attack a fire when carbon dioxide vapor isbeing discharged therefrom. Because it is very essential that liquidcarbon dioxide be delivered to the discharge nozzles H and M at theearliest moment possible after a fire is discovered, it becomesimperative that the initial charge of carbon dioxide vapor be exa morerapid rate than is possible with the discharge nozzles II and M, Forthat reason, the piping of the system is provided with a suitable numberof vapor venting devices which are designated by the reference characterIS in Fig. 1. It will be noted that one of these devices is provided forthe large capacity piping header 1 while a second venting device isprovided for the completely illustrated branch line 8. It is to beunderstood, however, that additional venting devices 15 may be employedand that they may be arranged in any suitable manner in the system tomost efficiently effect rapid discharge of the carbon dioxide vapor fromthe entire length of piping between the storage tank 5 and eachdischarge nozzle.

Each one of the vapor venting devices I5 is illustrated in Fig. 1 asbeing connected in a length of piping l6 that'is coupled to the header 1or a branch line 8. These pipe lines It are shown as being broken offbeyond the venting devices l5. This is intended to illustrate that thesepipes l6 may open to the atmosphere or they may extend to a suitablepoint outside of the building provided with the fire extinguishingsystem so that the vented carbon dioxide vapor may be exhausted to theoutside atmosphere.

The detail construction of each one of the carbon dioxide vapor ventingdevices is clearly illustrated by the disclosures of Figs. 2 to 4inclusive and will be described in connection with these figures. 4 lThe venting device includes a suitable valve housing or body l1 that isprovided with an inlet '3 so that the venting 4 extension 21 l3 and anoutlet l3. Between the inlet and the outlet, the body I! is providedwith a partition 23 that is formed with an opening 2i surrounded by avalve seat 22. In line with the axis of the opening 2|, the valve bodyI1 is provided with an opening through which passes the valve stem 24.This stem carries a valve head or member 23 that is adapted to be movedinto and out of engagement with the partition seat 22 for closing andopening the flow body.

- The valve head or member 23 normally should occupy the unseated devicewill be open for the discharge of carbon dioxide vapor. A spring 23 isthreaded over the valve stem 24 and is connected, in a mannertobedescribed, to the valve stem for normally holding the valve head ormember unseated.

The valve body I! is'provided with a hollow that surrounds most of theprojecting portion of the valve stem 24 and the spring path through thevalve position illustrated in Fig.

, devices II now will 23. This hollow extension 21 is flanged at 23 for7 having connected thereto the cap 23 by means of the screws 33. The cap23 and the flange 23 clamp between their opposed surfaces the peripheraledge of the flexible diaphragm 3|. The central portion of this diaphragmis connected to the outer end portion of the valve stem 24 by means ofthe discs 32 and 33 and the nut 34. These discs and the diaphragmfunction to connect the outer end of the spring 26 to the valve stem 24.

The space provided within the hollow extension 21 is vented to theatmosphere by the opening 35 so that atmospheric pressure will prevailin this space. The space 33 that is formed between the diaphragm 3| andthe cap 23 is sealed so as to provide a fluid pressure chamber for theapplication of fluid pressure to the outer surface of the diaphragm.When suflicient fluid pressure is thus applied to the diaphragm II, itwill overcome the force of the spring valve head or member 25 againstthe seat 22 for closing of! the flow path for carbon dioxide vapor thatis normally provided through the valve body i1.

Figs. 2 and 3 disclose a suitable length of tubing 31 that is connectedto the cap 23 at one end for communicating with the chamber 33 formedbetween the cap and the diaphragm 3 I. This tubing extends to anexpansion chamber 33 and is connected to the same by the nipple 33, seeFigs. 2 and 4. This chamber 33 is formed by a section of tubing 43 thatis closed at one end by the welded plate 4i The remaining end of thechamber is provided with an exterior flange 42. Connected to this flangeis a plate 43. The plate, however, is held in spaced relation to theflange 42 by means of the thin spacers 44 that surround the screws 45which fasten the plate 43 to the chamber flange 42. It will beappreciated, therefore, that the interior of the chamber 33 is open tothe atmosphere through the space or gap that is left between the flange42 and plate 43.

a The chamber wall 38 is provided with an opening 46 in which is fitteda nipple 41. This nipple is welded to the chamber wall at 43. A shortlength of tubing 43 is threadedly connected to the nipple 41 at one endand is threaded in an opening 50 formed in the wall of the valve body I!in close proximity to the inlet l3. A tip Si is suitably fastened to theinner end of the tube, bearing the reference numeral 52, and extendsinto the interior of the valve body II. This tip is prodioxide admittedto the tip its pressure will drop. The

26 and will move the vided with an end aperture 33 for placing the pipe32 and the interior of the chamber 33 in restricted open communicationwith the interior of the in let portion of the valve body l1. It will beappreciated, therefore, that any fluid flowing through the valve body IIwill be delivered in part to the interior of the expansion chamber 33.If nothing prevents its exit, the fluid delivered to the chamber 33 willbe exhausted to the atmosphere through the slot or gap that is providedbetween the peripheries of the chamber flange 42 and its plate 43. Also,the pressure prevailing in the chamber 33 to the chamber 33 through thetubing 31.

The operation of each of the vapor venting be described.

When the liquid carbon dioxide initially admitted to the system piping'|3 flashes to vapor, this vapor will be expelled through the valvebodies H of the venting devices I! and will be carried on to a desiredpoint by the associated pipe lines I. Some of this vapor will bedelivered to the expansion chambers 33 associated with the j devices i5.

This vapor, however, will be exhausted from the chambers through theslots or gaps provided for this purpose. If a suitable number of vaporventing devices I! is provided for the system, the initially formedvapor will be vented from the system in a very small number of seconds.

- when the piping of the system is supplied with liquid carbon dioxidethat does not flash to vapor at the location of each one of the ventingdevices II, a portion of this liquid will flow into the valve body I!and a part of this liquid will be delivered to the bore of the tip 5|through the aperture 53. Because the bore of the tip II is ofsubstantially greater diameter than the diameter of the aperture 53, theliquid carbon bore will expand and I bore of the pipe section 52 and theinterior of the chamber 38 will permit further expansion and pressuredrop of the liquid carbon dioxide tip aperture 33. This expansion of theliquid carbon dioxide will cause the pressure of the liquidto drop to avalue below pounds per square inch, absolute, with the result that theliquid carbon dioxide will be changed to a mixture of snow and vapor. Asthe snow attempts to escape from the chamber 33 through the slot or gapformed between the flange 42 and the plate 43, the snow willprogressively block up this slot or gap and freeze so as to finallycompletely close this end of the chamber 33. Pressure will build up inthe chamber 33 as the slot or gap is closed and this vapor pressure willbe applied to the diaphragm chamber 36 through the tubing 31. Whensufiicient vapor pressure develops in the chamber 36, the diaphragm 3|will deliver this pressure to the valve head 25 through its stem 24 andthe valve head will be seated to prevent further passage of carbondioxide through the valve body IT. The

valve head 25 will remain seated until the pres-- passing through the-which liquid carbon aeeaaec to deliver the carbon dioxide from itssource of of piping that is required supply to a remotely locatedhazard. It further I will be appreciated that the pressure chamber 38need not be placed in communication with the interior of the valve bodyI! adjacent its inlet 18 but may be connected to any portion of thevalve body and the piping I, 8, or Hi from dioxide can be obtained.

,It is to be understood that the form of this invention herewithv shown.and described is to be taken as the preferred example of the same, andthat various changes in the shape, size, and arrangement of parts may beresorted to without departing from the spirit of the invention or thescope of subjoined claims.

Having thus described the invention, 1 claim:

1. The combination with a fire extinguishing system comprising a sourceof supply of liquid carbon dioxide, piping extending from said source ofsupply to the point or points of discharge, liquid carbon dioxidedischarge means connected to the piping at the points of discharge, andvalve means in the piping adjacent the source of supply for admittingcarbon dioxide into the piping, of a plurality of normally open carbondioxide vapor venting valves connected in the piping at spaced intervalsbetween the said valve means and the discharge means, pressure fluidoperated means for closing each vapor venting valve, and meansassociated with each pressure fluid operated means and responsive to theformation of carbon dioxide snow and vapor resulting from the suddenexpansion of liquid carbon dioxide to apply vapor pressure to said lastmentioned means to cause said means to close its vapor venting device.

2. The combination with a flre extinguishing system comprising a sourceof supply of liquid carbon dioxide, piping extending from said source ofsupply to the point or points of discharge, liquid carbon dioxidedischarge means connected to the piping at the points of discharge, andvalve means in the piping adjacent the source of supply for admittingcarbon dioxide into the piping, of a plurality of normally open carbondioxide vapor venting valves connected in the piping at spaced intervalsbetween the said valve means and the discharge means, pressure fluidoperated means for closing each vapor venting valve, and chamber meansconnected to each pressure fluid operated means and responsive to theformation of carbon dioxide snow and vapor resulting from the suddenexpansion of liquid carbon dioxide to apply vapor pressure to said lastmentioned means to cause said means to close its vapor venting valve.

3. The combination with a flre extinguishing system comprising a sourceof supply of liquid carbon dioxide, piping extending from said source ofsupply to the point or points of discharge, liquid carbon dioxidedischarge means connected to the piping at the points of discharge, andvalve means in the piping adjacent the source of supply for admittingcarbon dioxide into the piping, of a plurality of normally open carbondioxide vapor venting valves connected in the piping at spaced intervalsbetween the said valve means and the discharge meansrpressure fluidoperated means for closing each vapor venting valve, and a chambercommunicating with each pressure fluid operated means and with thepiping at the location or the vapor venting valve for said means, saidchamber having a restricted outlet opening through which carbondioxide'vapor will discharge to the atmosphere but which will besufllciently blocked by carbon dioxide snow formed in the chamber whenliquid carbon dioxide expands therein to thereby bring about theapplication of vapor pressure to the pressure fluid operated means tocause said means to close its vapor venting valve.

4. The combination with a fire extinguishing system comprising a sourceof supply of liquid carbon dioxide, piping extending from said source ofsupply to the point or points of discharge, liquid carbon dioxidedischarge means connected to the piping at the points of discharge, andvalve means in the piping adjacent the source of supply for admittingcarbon dioxide into the piping, of a plurality of normally open carbondioxide vapor venting valves connected in the piping at spaced intervalsbetween the said valve means and the discharge means, pressure fluidoperated means for closing each vapor venting valve, and means, having arestricted opening to the atmosphere, providing communication betweeneach pressure fluid operated means and the piping at the location of thevapor venting valve for said presa,

sure fluid operated means, said restricted opening allowing carbondioxide vapor to discharge therethrough when said vapor fills the pipingat its location but blocking up with snow when liquid carbon dioxidereaches the piping at its location.

5. In combination, a source of liquid carbon dioxide, a pipe line,having a device for discharging liquid carbon dioxide, connected to saidsource, means for controlling the admission of carbon dioxide into thepipe line from said source, a carbon dioxide vapor venting valveconnected to the pipe line and normally open to the atmosphere, andmeans for closing said vapor venting valve operative in response to theformation of snow resulting from the expansion of liquid carbon dioxideobtained from the pipe line.

6. In combination, a source of liquid carbon dioxide, a pipe line,having a device for discharging liquid carbon dioxide, connected to saidsource, means for controlling the admission 0! carbon dioxide into thepipe line from said source, a fluid pressure closed carbon dioxide vaporventing valve connected to the pipe line and normally open to theatmosphere, and means operative in response to the formation of snowresulting from the expansion of liquid carbon dioxide obtained from thepipe line, for applying vapor pressure to the venting valve to closesame.

7. The combination with a pipe line into which liquid carbon dioxide isreleased when required at a point of use served by said pipe line, ofnormally open meansior venting from the pipe line the vapor that isformed therein when the liquid carbon dioxide is flrst released into thepipe line, said venting means comprising normally open valve, and meansfor closing the valve operative in response to a change in phase of thecarbon dioxide from liquid to solid.

8. The combination with a pipe line into which liquid carbon dioxide isreleased when required at a point of use served by said pipe line, ofnormally open means for venting from the pipe line the vapor that isformed therein when the liquid carbon dioxide is first released into thepipe line, and means to close the venting means responsive to a changein phase of carbon dioxide from liquid to solid when liquid carbondioxide is in the pipe line at the venting means.

9. Carbon dioxide vapor venting means, comprising a valve body having aflow path therethrough, a valve member in the body movable between twopositions for opening and closing said flow path, yieldable meansnormally holding said valve member in its open position, pressure fluidoperated means for moving said valve to its closed position, and meansfor applying carbon dioxide vapor pressure to said pressure fluidoperated means operative in response to a change in phase of carbondioxide from liquid to solid when liquid carbon dioxide passes throughthe flow path or the valve body.

10. Carbon dioxide vapor venting means, comprising a valve body having aflow path therethrough, a valve member in the body movable between twopositions for opening and closing said flow path, yieldable meansnormally holding said valve member in its open position, pressure fluidoperated means for moving said valve to its closed position, and meansfor applying carbon dioxide vapor pressure to said pressure fluidoperated means to move the valve member to its closed position whenliquid carbon dioxide is passing through the flow path of the valvebody, said last mentioned means comprising a chamber having a restrictedoutlet opening through which carbon dioxide vapor will discharge to theatmosphere but which will be blocked by carbon dioxide snow formed inthe chamber when liquid carbon dioxide expands therein, and piping meansconnecting the chamber to the valve body flow path and to the pressurefluid operated means.

11. Carbon dioxide vapor venting means comprising means forming a paththrough which carbon dioxide vapor will be permittedto flow, and carbondioxide pressure operated means for closing said path when liquid carbondioxide starts to flow through the path, said last mentioned means beingresponsive to the pressure developed when the phase of the carbondioxide changes from liquid to solid.

12. Carbon dioxide vapor venting means, comprising means forming a paththrough which carbon dioxide vapor will be permitted to flow, carbondioxide pressure operated means for closing said path, and means forapplying carbon dioxide vapor pressure to said pressure operated meansoperative in response to a change in phase of carbon dioxide from liquidto solid when liquid carbon dioxide passes through said path.

13. Carbon dioxide vapor venting/means, comprising a valve having anorm-ally open flow path therethrough, carbon dioxide pressure operatedmeans for closing said valve, and means for applying carbon dioxidevapor pressure to said pressure operated means operative in response toa change in phase of carbon dioxide in said pressure applying means fromliquid to solid.

14. Means for venting vapor from a pipe line into which liquid carbondioxide is occasionally released, comprising means forming a flow paththrough which carbon dioxide will be permitted to flow, means forclosing said flow path, pressure fluid operated means for actuating saidflow path closing means to close said path, means forming a carbondioxide vapor by-pass line between the pressure fluid operated means andsaid flow path,

and means connected in said by-pass line to delay the actuation of saidpressure fluid operated means.

15. Means for venting vapor from a pipe line into which liquid carbondioxide is occasionally released, comprising a valve having a normallyopen flow path therethrough, pressure fluid operated means for closingsaid flow path when a predetermined pressure has been built up in saidpressure fluid operated means, piping connecting said pressure fluidoperated means and said flow path, and means connected in said piping todelay the building up of pressure in said pressure fluid operated means.

16. Means for venting vapor from a pipe line into which liquid carbondioxide is occasionally released, comprising a valve having a normallyopen flow path therethrough, a member in the valve movable between twopositions .for opening and closing the flow path, pressure fluidoperated means for moving said valve member into its closed positionwhen a predetermined working pressure has been built up in the pressurefluid operated means, means forming a carbon dioxide vapor by-pass linebetween the pressure fluid operated means and said the valve, and meansconnected in said by-pass line to delay the actuation of said pressurefluid operated means.

17. The combination with a fire extinguishing system comprising a sourceof supply of liquid carbon dioxide, piping extending from said source ofsupply to the point or points of discharge, liquid carbon dioxidedischarge means connected to the piping at the points of discharge, andvalve means in the piping adjacent the source of supply for admittingliquid carbon dioxide into the piping, of a plurality of normally openventing valves connected in the piping at spaced intervals between thesaid valve means and the discharge means for quickly emptying the pipesof carbon dioxide vapor that is formed therein as a. result of flashingof the liquid carbon dioxide initially released into the piping,pressure fluid operated means for closing said venting valves as soon asa proper working pressure of carbon dioxide vapor has been built uptherein, means forming a carbon dioxide flow path between each pressurefluid operated means and the piping upstream of this associated ventingvalve, and means located in said flow path for throttling the flow ofcarbon dioxide therethrough to delay the development of said workingpressure in the pressure fluid operated means for a predeterminedinterval of time to prevent the premature closing of the venting valve.

18. In combination, a pipe line into which liquid carbon dioxide isreleased when required for discharge at a point of us served by saidpipeline, a normally open vent valve connected to the pipe lines forrelease to the atmosphere of the vapor that is formed in the pipe linewhen liquid carbon dioxide is first released into the pipe line,pressure fluid operated means for closing said vent valve as soon as aproper working pressure of carbon dioxide vapor has been built uptherein, means forming a carbon dioxide flow path between said pressurefluid operated means in the pipe line upstream of the vent valve, andmeans located in said flow path for throttling the flow of carbondioxide therethrough to provide for the elapse of a predetermined lengthof time, after liquid carbon dioxide is released into the pipe line,befor the said working pressure is built up in said pressure fluidoperated means.

19. Means for venting vapor from a pipe line vapor flow path througharouses into which liquid released, comprising a valve body having acarbon dioxide vapor flow path therethrough, a valve member in th valvebody movable between two positions for opening and closing said flowpath, resilient valve member in its open position, pressure fluidoperated means for moving said valve member into its closed positionwhen a predetermined working pressure has been built up therein, meansforming a carbon dioxide vapor by-pass line between the pressure fluidoperated means and said vapor flow path through the valve body, andmeans located in said by-pass line for throttling the flow of carbondioxide therethrough to delay the development of the working pressure inthe pressure fluid means for a predetermined interval of time aftercarbon dioxide has been delivered to the flow path through the valvebody.

20. Means for venting vapor from a pipe line into which liquid carbondioxide is occasionally released, comprising a valve body having acarbon dioxide vapor flow path therethrough, a valve member in the valvebody movable between two positions for opening and closing said nowpath, resilient means normally holding said valve member in its openposition, pressure fluid operated means for moving said valve memberinto its closed position when a predetermined working pressure has beenbuilt up therein, means iorming a carbon dioxide vapor by-pass linebetween the pressure fluid operated means and said vapor flow paththrough the valve body, means located in said by-pass line forthrottling the flow of carbon dioxide therethrough to delay thedevelopment of the working pressure in the pressure fluid operated meansfor a predetermined interval of time after carbon dioxide has beendelivered to the flow path through the valve body, and a receiverconnected in the by-pass line between the throttling means and thepressure fluid operated means toiincrease the effective volumetriccapacity of the pressure fluid operated means to further delay thedevelopment of said working pressure in the pressure fluid operatedmeans.

21. Means for venting vapor from a pipe line into which liquid carbondioxide is occasionally released, comprising a valve body having acarbon dioxide vapor flow path therethrough, a valve member in the valvebody movable between two positions for opening and closing said flowpath, resilient means normally holding said valve member in its openposition, pressure fluid operated means for moving said valve memberinto its closed position when a predetermined working pressure has beenbuilt up therein, means forming a carbon dioxide vapor by-pass linebetween the pressure fluid operated means and said vapor flow paththrough the valve body, means located in said by-pass line forthrottling carbon dioxide is occasionally means normally holding said 12the flow of carbon dioxide therethrough to delay the development of theworking pressure in the pressure fluid operated means for apredetermined interval of time after carbon dioxide has been deliveredto the flow path through the valve body, a receiver connected in theby-pass line between the throttling means and the pressure fluidoperated means to increase the efiective volumetric capacity of thepressure fluid operated means to further delay the develop ment of saidworking pressure in the pressure fluid operated means, and means forslowly exhausting the vapor from the pressure fluid operated means,after the release of liquid canbon dioxide into said pipe line hasceased, to permit the resilient means to return the vent valve member toits open position.

22. Means for venting vapor from a pipe line into which liquid carbondioxide is occasionally released, comprising a valve body having acarbon dioxide vapor flow path therethrough. a valve member in the valvebody movable between two positions for opening and closing said flowpaths, resilient means normally holding said valve member in its openposition, pressure fluid operated means for moving said valve memberinto its closed position when a predetermined working pressure has beenbuilt up therein, means forming a carbon dioxide vapor by-pass linebetween the pressure fluid operated means and said vapor flow paththrough the valve body, means located in said by-pass line forthrottling the flow of carbon dioxide therethrough to delay thedevelopment of the working pressure in the pressure fluid operated meansfor a predetermined interval of time after carbon dioxide has beendelivered to the flow path through the valve body, a receiver connectedin the by-pass line between the throttling means and the pressure fluidoperated means to increase the effective volumetric capacity of thepressure fluid operated means to further delay the development of saidworking pressure in the pressure fluid operated means, and means forslowly ex- 'hausting the vapor from the pressure fluid operated means,after the release of liquid carbon dioxide into said pipe line hasceased. to permit the resilient means to return the vapor vent valvemember to its open position.

' WALTER W. VOSS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 625,759 Hargrave May 30, 18992,261,080 Stellhorn Oct. 28, 1941 2,356,990 ,Getz Aug. 29. 19

